Blowing Oil After Top End Rebuild

[Wes Bender]

That's the way they were on the set I got from Leonard, Cliff. Very good instructions with them. All but the oil rings needed a slight grind. Leonard suggested that I check them and grind as needed. My gauges were the specific cylinders in which they were to be installed, although I could have swapped the cylinders around and it wouldn't have made a difference. Those Shasta cylinders are really good.

By edit - OOPS. You said supplied by AA. Gotta go. It's cocktail hour..... Ask me again later.

[Rusty Ferrell]

Eric, ring gaps were staggered as Greg said. The end gaps varied from 0.022” to 0.025 for second ring. I agree that rings rotate and can on occasion have the gaps align, but has always been my understanding that to stagger the gaps assists in breakin. I worked for an engine company right out of college but our goals were millions mile engines and we broke engines in based on measuring blowby with a given orifice. Rings were always staggered on assembly. Hope this helps Eric. Best to you,

[C J Murray]

The official JE instruction sheet...

https://www.jepistons.com/PDFs/TechCorn ... rc4032.pdf

When you buy JE pistons from AA what brand and type of rings come with them?

Are those rings installed onto the pistons?

Are they pre-gapped?

[Greg Carter]

Mr. Murray,

We called JE to buy new rings and JE says they don’t sell rings for those pistons. With that, I assume they’re AA brand but I wasn’t able to talk to an AA tech guy to find out. They were pre-installed but we did check alignment (per the JE instruction sheet) and ring gap. We ended up buying a set of Total Seals to get a known good quality brand of ring.

Greg

[Eric Wills]

Eric, ring gaps were staggered as Greg said. The end gaps varied from 0.022” to 0.025 for second ring. I agree that rings rotate and can on occasion have the gaps align, but has always been my understanding that to stagger the gaps assists in breakin. I worked for an engine company right out of college but our goals were millions mile engines and we broke engines in based on measuring blowby with a given orifice. Rings were always staggered on assembly. Hope this helps Eric. Best to you,

Rusty,

Thanks for the info. I was really just curious if AA made a mistake installing the rings with incorrect end gaps. I hope my question about the ring gaps AA set is not confused with Cliff's comment about staggering ring position.

Best sir,

EW

[Eric Wills]

The official JE instruction sheet...

https://www.jepistons.com/PDFs/TechCorn ... rc4032.pdf

When you buy JE pistons from AA what brand and type of rings come with them?

Are those rings installed onto the pistons?

Are they pre-gapped?

Fairly sure they are Hastings rings. Installed and gapped. It's up to the installer to clean, stagger and make sure there are no defects. Good idea to take a close look and compare your wrist pins. Check the balance work that was done by AA. If you are using the biral cylinders, check carefully for cracks and don't forget to clearance the cooling fins in all the right places.....

[C J Murray]

Mr. Murray,

We called JE to buy new rings and JE says they don’t sell rings for those pistons. With that, I assume they’re AA brand but I wasn’t able to talk to an AA tech guy to find out. They were pre-installed but we did check alignment (per the JE instruction sheet) and ring gap. We ended up buying a set of Total Seals to get a known good quality brand of ring.

Greg

The plot thickens! Another reason to pay the Shasta or LN price. Yes, JE pistons are quality but who made the pins and the rings?

What style pin retaining clips are used? Could we see a picture? It matters.

[Greg Carter]

Reviving this thread.

Rusty and I (well....mostly Rusty) pulled the engine down last month and cleaned / checked everything (everything was in spec). All we could figure is that the rings failed to seat due to using a synthetic oil and not a straight weight or break in oil. We ended up putting in Total Seal rings (gapless 2nd) and using straight 30W for break in. I also installed the correct C breather hose that runs to the air cleaner.

Everything seemed to be progressing nicely until the other day. I was driving on the interstate at 65 MPH or so and had been cruising for about 20 minutes when the car started smoking heavily again for about 4-5 minutes. I slowed a bit and eventually it cleared as I reached my exit. When I got to a place where I could check it the car was running normally with no smoke or issues. The right carb was covered in oil but otherwise there were no leaks. When I revived the engine after the car sat idling for a few minutes it smoked some but quickly went away after I drove away.

I went home and swapped the stock breather hose for the Euro setup I have that vents under the car. After that, I drove the car frequently for about 2 weeks without any issues. Yesterday I drove the snot out of it for about an hour on some twisty, flat backroads and still had no issues. There was no smoking or oil leaks.

At that point, the car had about 600-700 miles on it since we put it back together again.

Today, with the Euro breather venting under the car, I drove it on the interstate. After about 20 minutes I smelled burnt oil in the heater vents so stopped and took a look. The car was dripping oil from the pulley seal, vent tube and, due to all the oil, from the body under the bumper. It’s was literally dripping oil like it had previously although this time it only appeared to come from the pulley seal and vent tube unlike last time where it was also dripping from the valve covers and pushrod tube seals.

Things I THINK I’ve figured out:

- the crankcase is obviously building up pressure / vacuum when run at a near constant RPM for more than 10 minutes. I drove at varying RPMs yesterday on my weekend cruise and only touched 60 MPH for about 5 minutes. Otherwise, RPMs varied widely from stop and go traffic to rowing gears driving on the backroads.

- the smoke from the tail pipes while at highway speed appears to be caused by the excessive pressure building up then forcing oil / oil vapor / water vapor out of the vent tube and into the right carb through the stock breather tube. With the vent tube routed under the car it doesn’t smoke like a mosquito sprayer but there’s was ALOT of oil that puked out of the tube (the cause of the oil covered rear valance / muffler). Also, the vent in the air cleaner is clear and not clogged up so I doubt that’s an issue. It pumps oil through the breather hose no matter where it’s routed to.

- it appears the stock breather hose routed to the right carb helps relieve case pressure since, the last time it did blow smoke it didn’t puke oil from the pulley seal but did ingest oil into the carb causing the smoke. It seems, the vacuums on created by the carb seems to relieve enough case pressure to prevent the pulley seal from leaking but I’m not sure.

- once it’s started smoking and / or pumping oil the car will smoke out the exhaust pipes when you rev the engine while at idle. If you shut it down and let it sit for about 20 minutes it will stop smoking when revving the engine once you restart it.

- assuming my oil temp gauge is accurate, it doesn’t appear to be an issue with overheating based on the oil temp being in the black but at the bottom of the arc.

My problem seems to be a buildup of pressure / vacuum after a sustained RPM cruise at higher speed. I don’t know if exhaust rocker squirters might be an isssue (doubt it) or if my cam / carb combination may be creating too much vacuum (also doubt it). I’m just trying to consider everything.

At this point I’m at my wits end trying to figure this out so any thought would be appreciated.

[Tony Proasi]

Years ago I had a 914/4 that would do the same thing cruising down the highway. I found it had a valve guide that would work its way loose. Once it cooled down all good.

[Matthew Devereux]

Perhaps its an oil foaming issue. I would check your oil level and try dropping it. Maybe check it with another dipstick.

[Dick Weiss]

After reading all the posts about oil leaks and "smokes", my findings & suggestions;

I record the ring gap locations during cylinder removals since I re-chart their locations @ 90 or 120 degree during cylinder installments
depending on 4-ring or 3-ring piston respectively. However, there's a maximum ring-to-groove/side clearance of .006" besides the ring gaps depending on which cylinders exist per the old/NLA chromed-aluminum, or other types of Ferral, Biral, or "Nickies".

Cylinder walls should be straight and round w/in specs--especially @ the top 1/4" of 'ring reversal', and the maximum wear limit of the piston skirt-to-the-cylinder ID; If the piston "rocks" during its stroke, the rings won't seal correctly, and excessive ring-to-groove- clearance will actually allow a "pumping action". (rings gaps opening & closing)

Then there's the valve stem wear-to-guide-ID--stems not straight as Al Zim mentioned including the guide ID wear. The original copper guides wore more than the later bronze version & intake guides needed the seals to prevent excessive 'lubing'; The bronze guide material specs require lubrication so I don't use stem seals and if the guides are reamed properly after insertion into the head,
no problem during the test and driving ruins. BTW, during valve seat re-finishing (3-angles), I use various solid pilots when cutting
the seats--NOT the 'flexible' version and I don't have a seat grinder; I have better control by hand-cutting just like Porsche did.

Crank pulley leaks will have a problem of the seal preventing oil getting past the seal; Tiny rust pits or a light groove from a hardened/aged seal can be re-finished w/in .005" grind-cleanup concentric to its rotation; I saved many & have some for exchange.
However, if the hub cracked @ the keyway, I machine the hub for a full-length pressed-on sleeve and re-finish to size.
I don't care for Speedi Sleeves including flywheel hubs--that's been covered in previous "talks".

Torqueing the pulley bolt, 45-50 ft.lbs. is sufficient, but I add RTV sealant to both sides of the washer at assembly & NOT forgetting to add the 54mm dia. "oil slinger"/shim before adding the pulley! Other leaks? Vertical cheese head screws on both sides of the intake manifolds loose or missing, aged headbolt O-rings leaking onto the pushrod tubes, steel sump plate surfaces not flat (aluminum
plates are machined), the proper sealing rings on the oil junction block, it's senders, and oil filter lines; etc.
Finally, the O-ring on the distributor, the gaskets around the fuel pump, & the aged shaft-seal on the later/horizontal fuel pump.

Dick

[Ron LaDow]

- the crankcase is obviously building up pressure / vacuum when run at a near constant RPM for more than 10 minutes. I drove at varying RPMs yesterday on my weekend cruise and only touched 60 MPH for about 5 minutes. Otherwise, RPMs varied widely from stop and go traffic to rowing gears driving on the backroads.

Greg,
There are certain immutables, and you're dealing with one or the other. It's a shame you ended up with the parts which are causing the problems, but by now, the cheapest solution is to get that thing on a dyno with good monitoring processes.
Got a dyno nearby?

[Dan Epperly]

You have to start wondering if maybe the new cylinders are to blame. Maybe out of round? New parts can fail and drive you crazy because you assume they are good, when sometimes they are not.

[George Hussey]

I would certainly think that you broke a ring or two while installing them. (I am sure that you checked the oil level, correct? Not way overfull?

[Matthew Devereux]

A leak down test will quickly tell you what your ring seal is leak. It would have to be awfully bad to be blowing oil . I don't see how the problem would come and go.